This research paper moves from an analysis of the main milestones which have contributed to the evolution of trend forecasting from a qualitative expert-driven methodology to a data-driven one: the spreading of systematic future-thinking and scenario planning with the birth of the discipline of future studies; the invention of trend books and subsequently of online trend platforms to help fashion and design companies limit waste and markdowns, inspire creative minds and guide the development of new product/service systems; the age of trend gurus and futurologists levering a qualitative, expert-driven approach to trend forecasting, therefore playing the role of gatekeepers in trend diffusion dynamics; the popularization of the curve of trend diffusion’s theoretical construct and the boom of the coolhunting practice, resulting from the application of the research methods typical of ethnography to the participant observation of youth subcultures’ styles and behaviors; finally the rise of data-driven trend forecasting platforms leveraging the power of predictive analytics, big data and AI technologies to track and forecast new trends.